In laying tile, spacers are used between each tile to separate the tiles by a consistent distance determined by the size of the spacers. The tiles are placed on mortar or another adhesive to attach the tiles to the underlying surface. After the mortar is cured or dried sufficient to hold the tiles in place, then the spacers are removed. The gaps between each tile are then filled with grout.
For a wall, the bottom row of tiles rests on a surface, typically the floor or rim of a tub, however, other types of supports may be used. The second row of tiles rests on the bottom row of tiles or on spacers that rest on the bottom row of tiles. Rows of tiles are stacked on top of each other up to the top row.
For some types of wall designs, decorative patterns are used that are not able to support the weight of additional rows of tiles above the pattern. Some such decorative patterns have stone or tile pieces with uneven size or spacing attached to a mesh backing. In order to install such a decorative pattern, the pattern is applied onto the wall with mortar or adhesive, then the tile rows above the pattern are applied after the mortar for the decorative pattern has dried. This prevents the tiles above from disturbing the pattern. Grout can then be applied after all of the mortar has dried.